ABSTRACT
No other compound is more essential to life than water, for without it there would be no life of any kind. Bacteria, plants, animals, and humans all require exogenous water. The human body contains more water than any other component. The water content of the body varies according to age, sex, bone density, lean body mass, and gross body weight. Water is biologically important because of its many unusual physical and chemical properties. Water intake should approximate the water output on a daily basis. The body has essentially no water reserves. The kidneys along with the gastrointestinal tract and brain homeostatically regulate the amount of water in the body, at least the fatfree components. The consumption of large quantities of protein facilitates water loss through urea production and excretion. This increased excretion of urine can hasten body dehydration. Diarrhea and vomiting can also cause body dehydration.
